1. Field of the Invention
The present invention relates to an ATM exchange, in particular it relates to a technique to detecting a fault in the ATM exchange.
2. Prior Art
An ATM exchange consists of a plurality of devices such as a cell switching device, a cell multiplexing device, a cell demultiplexing device, and interface devices. Since each of the devices, however, is not provided with a self-detection system for detecting a communication fault, when the communication between the devices is brokendown (generation of a hardware stack), the system cannot detect the fault. And therefore, even if a standby system is prepared, it is not possible for quickly switch the operation from an actual system to a standby system, and the cell flow may be stopped.
An ATM exchange cannot announce a generation of a fault to a maintenance person, and the maintenance person generally knows generation of the fault by reports from subscribers for the first time. As a result, the communication service is interrupted until reports from subscribers, and there is a problem of the maintainability.